Water ring for concrete pipe forms



Feb. 15, 1938. J. c. FRENCH WATER RING FOR CONCRETE PIPE FORMS FiledAug. 3, 1937 Patented Feb. 15, 1938 WATER RING FOR. CONCRETE PIPE. FORMSJay C. .French, San Gabriel, Calif., assignor to American Concrete &Steel Pipe Company, a corporation of Delaware Application August 3,1937, Serial No. 157,146

3 Claims.

This invention relates generally to the manufacture of centrifugallyspun concrete pipe and particularly to the forms used in the manufactureof such pipe. I

In the manufacture of centrifugally spun concrete pipe, the pipe form isrotated by suitable apparatus and the concrete introduced into the formwhile it is rotating. Due to the compacting of the concrete bycentrifugal force, it is necessary to fill the form to av greaterthickness of concrete than the desired thickness of the completed pipe.It is also desirable to have the end rings of the form the same width asthe thickness of the completed pipe so that they may function as guidemeans for troweling and finishing the interior of the pipe. Also, if therings of the form are made wider than the desired thickness of thecompleted pipe it is difiicult to remove the water and slurry after the:concrete has been compacted against the sides of the form. In view ofthis, some provision must be made for temporarily increasing the widthof the end ring forms to prevent escape of concrete and water during thecompacting period. Steel split rings have been used for this purpose,but without success, as they permit the escape of water and it isdesirable to retain the water to aid in compacting the concrete and inproviding a smooth dense impervious inner surface. thereto. The splitrings are also unsatisfactory in that they often become loose during thespinning operation and fall out of the pipe.

In View) of the above disadvantages of the present methods of retainingthe concrete and water in the pipe during the compacting operation it isa primary object of this invention to provide an improved water ring forconcrete pipe forms which will effectively retain concrete and water ina spinning concrete pipe form. It is also an object of this invention toprovide a water ring which is of simple construction and which may beeasily installed and easily removed and which, when installed in an endring of a concrete pipe form will remain in place during the rotation ofthe pipe form.

These and other objects will be apparent from the accompanying drawingwhich is for illustrative purposes only, and in which Fig. 1 is alongitudinal sectional elevation of a typical centrifugal pipe formshowing two of the water rings of this invention installed therein.

Fig. 2 is an end elevation of the water ring.

Fig. 3 is a cross section of the Water ring taken on line 3--3 of Fig.2.

Fig. 4 is a fragmentary elevation of one of the hinged connections ofthe toggle joint.

Fig. 5 is an inverted sectional plan view on line 55 of Fig. 4.

More particularly describing the invention, 5 reference numeral llgenerally indicates a cylindrical concrete pipe form which is adapted tobe rotated by means of suitable apparatus such as a belt or engagingrollers. The form is provided with detachable end rings l2 and I3 forthe purpose of holding the concrete in the cylindrical form I I duringthe spinning operation and for the purpose of forming the bell andspigot ends of the pipe. These end rings may be held in place by anysuitable attachment means and to accomplish this the rings have beenshown provided with eye brackets M which are adapted to accommodate bolthooks 15. These bolt hooks extend through hole It of brackets IS on thecylindrical form H and are threaded at their ends to accommodate nutsl1.

Reference numeral l8 indicates concrete, the concrete being shown in theposition it occupies when compacted to the shape of the completed pipesection. The ring of this invention, generally indicated by referencenumeral I9, is shown in position at each end of the form and adjacentthe inner end faces I2 and [3 of the rings l2 and I 3.

In the manufacture of a section of concrete pipe the concrete isintroduced into the cylindrical form ll during rotation of that memberuntil it is of a thickness equal to the distance between broken line ZEIand the interior surface of the form H. In other words, when the form IIis rotated, broken line 20 indicates the inner limit of the concreteprior to the compacting of the concrete by centrifugal force.

Referring to Figures 2 to 5 inclusive, for details in construction, thering l9 comprises a metal channel ring member 22 which is provided witha toggle means generally indicated by reference numeral 23. The togglemeans comprises the short channel links 24 and 25 which are pivotallyconnected at 26 and which are joined to the metal channel ring 22 by thepivotal connections 2! and 28.

A rubber ring 30 is mounted in the channel 22 by any suitable means,such as rivets 3|. It has also been found that the rubber ring may besecured to the channel member by means of cement. This ring iscontinuous and unbroken and is preferably not secured to the links 24and 25. Thus the ring hangs free of the links 24 and 25 when the togglemeans is collapsed to the broken line position of Fig. 2. The ringextends in width considerably beyond the channel member 22 and isadapted to form a fluid seal between itself and the inner end face ofthe end ring into which it is fitted.

A means of forming the toggle joint is shown in Figures 4 and 5 whereininner ends 24' of the link 24 fit inside of the channel 22 and are heldin place by means of rivets 34. The rubber ring 38 is suitably cut outat each of the pivotal points as at 35 to accommodate the hingedconnection.

In the manufacture of centrifugally spun concrete pipe a ring I9 isinserted inside of each of the end rings l2 and i3 and the toggle meansexpanded to the full line position shown in Fig. 2, thereby effecting afluid seal between each of the Water rings l9 and the inner end faces l2and I3 respectively of the end rings of the form. The entire form isthen rotated and concrete introduced until the inner limit of theconcrete is approximately even with the inner portion of the water ringor, in other Words, to the broken line of Fig. 1. During the rotation ofthe form the concrete is compacted and the water and air largely removedtherefrom.

In the latter stages of the formation of the pipe the space between theline 20 and line 35, which line indicates the inner surface of thecompleted pipe, is largely slurry and water. During the rotation of theform the water rings l9, by reason of the fact that they include arubber ring30 in pressure engagement with the inner end surfaces l2 andI3, effectively prevent escape or leakage of Water from the concrete.When the concrete is compacted and set, rotation of the form is stoppedand the rings may readily be removed from the forms by collapsing of thetoggle means. The water and slurry may then be removed and troweling orfinishing of the inner surface of the pipe may be accomplished,

using the inner end faces I2 and I3 of the end rings as a guide for thefinishing means.

In the description of this invention the ring 30 has been described asbeing rubber, however it is within the scope of this invention that anysuitable resilient material might be used in place of rubber. The metalring 22, although shown and described as a channel member might be madein some other shape, as for example, a flat band ring.

I claim as my invention:

1. A water ring for concrete pipe forms comprising: a channel ringmember having a toggle joint therein; and a continuous ring formed ofresilient material secured to said channel ring member in the channelportion thereof, said continuous ring of resilient material having agreater outside diameter than said channel member; said channel ringmember forming a continuous ring when in expanded position.

2. A water ring for concrete pipe forms comprising: a channel ringmember having a toggle joint therein the channel portion of said ringbeing on the outside thereof; and a rubber ring secured to said channelmember in the channel portion thereof, said rubber ring having a greateroutside diameter than said channel member; said channel ring memberforming a continuous ring when in expanded position.

3. A water ring for concrete pipe forms comprising: a contractible metalring member, said ring member being continuous when in normal expandedposition; a continuous ring of resilient material mounted on theperipheral surface of said ring member; and means for expanding themetal ring to bring the ring of resilient material into pressureengagement with the interior of the pipe form.

JAY C. FRENCH.

